The present invention relates to a device for assisting the loosening or tightening of nuts, and is particularly concerned with a device for loosening or tightening of wheel nuts on automobiles, trucks, trailers, agricultural machinery and like vehicles.
Wheel nuts are notorious for locking up and being difficult to undo. This can be due to over-tightening in the first place, corrosion-binding to the stem or, more frequently, due to the rotation of the wheel in use which has a tightening effect.
Various tools have been developed to loosen wheel nuts, ranging from the common 120xc2x0 xe2x80x9cL-shapedxe2x80x9d wheel brace used primarily for wheel nuts of small vehicles through the four-way or X-brace to more sophisticated lever arrangements for larger vehicles.
Tools used to loosen wheel nuts on large vehicles such as trucks are generally quite different from those used to loosen wheel nuts on automobiles because of the larger wheels, larger nuts and substantially higher torque which has to be applied. A type of tool commonly used for trucks comprises a socket extension and a sliding T-bar. The socket extension is merely a rod with a socket coupling at one end enabling connection with the nut (which is often set back some distance from the outer rim of the wheel) and another socket coupling at the other end for connection to a housing on the sliding T-bar. The sliding T-bar is simply a lever with a housing which slides along it. The housing, which is typically of caste metal construction, has a portion which is adapted to slot into the socket coupling of the socket extension. This tool has the disadvantage that for wheel nuts which are locked very tight, the lever frequently bends adjacent the housing and the wheel nut cannot be easily removed.
The problem with tools such as braces provided with most automobiles is that they can be difficult for many people to apply the necessary torque to the nuts for removal. This is particularly the case for many women, the disabled and the elderly. For instance a typical xe2x80x9cL-shapedxe2x80x9d wheel brace supplied with most automobiles today is a small device having a socket designed to fit about the wheel nut, an elbow located within about 20 mm from a closed end of the socket, and an arm extending approximately 20 mm from the elbow. As noted above, there is typically an angle of approximately 120xc2x0 between the arm and an axis of the socket. To use such a wheel brace it is essential for the user to support the elbow of the wheel brace with one hand, whilst attempting to rotate the socket by pressing up or down on the shaft with the other hand. As a result, the torque that can be applied in attempting to loosen the wheel nut is limited to the torque which can be produced by the application of the force of one hand to the arm of the brace. This is frequently insufficient to loosen the nut and the user will then use both hands to apply force to the arm of the brace. However, having taken one hand off the brace""s elbow, the socket tends to slip off the wheel nut since the force applied to the arm creates a second torque which is in the plane of the axis of the socket. The result of all this is that the wheel nut becomes frustratingly difficult to loosen.
It is therefore an object of the invention to address these problems by providing a device which has a useful mechanical advantage to enable effective loosening, and tightening of wheel nuts and/or which at least provides the public with a useful alternative to existing products.
According to the present invention there is provided a device for assisting the loosening of wheel nuts comprising a ground-engaging wheel brace support and a developed lever, wherein
(i) said ground engaging wheel brace support comprises a vertically extending element having a plurality of projections between its end for supporting a wheel brace in a substantially horizontal arrangement with respect to a wheel nut to be loosened, and
(ii) said developed lever includes means to capture and hold the wheel brace in such a way that the application of a downward force on the end of the developed lever is transmitted over a substantial section of the wheel brace to increase the rotational torque on the nut while minimising the tendency of the brace to bend.
The term xe2x80x9cwheel bracexe2x80x9d need throughout the specification and claims is intended to encompass all conventional devices for loosening and tightening wheel nuts, such as cross-braces, xe2x80x9cL-shapedxe2x80x9d wheel braces, socket extensions, and so forth.
The ground-engaging wheel brace support is preferably fabricated from a strip of steel plate which is contoured for maximum strength and stability, and which has a series of cut-out sections formed along its length for accepting and supporting a section of the wheel brace. Typically, the wheel brace support has two series of cut-out sections formed along its entire opposing edges, wherein each series of cut-out sections along one edge is regularly spaced but stepped in relation to the cut-out sections along the opposing edge. Preferably, the cut-out sections will have inclined openings so that the brace which projects therein will not slide out. The cut-out sections define the projections on which the brace rests.
A base plate, such as a small pad can project perpendicularly from the lower, in use, end of the upright stand or support, to enable proper contact with the ground, or surface on which the vehicle is resting and to ensure that the upright stand or support is maintained in a substantially vertical orientation when in use. Such a base plate is preferably formed integrally with the upright stand or support.
The developed lever is suitably at least twice as long as the wheel brace arm to which it is fitted. Preferably, the length of the developed lever is about 3 or 4 times the length of the wheel brace arm. Since such a length would normally result in an unwieldy lever for stowage purposes, a telescopic arrangement is preferred.
Most preferably, the developed lever comprises a hollow steel tube having a square or circular profile, with a smaller diameter tube slidable therein and extendable to a maximum extent governed by a spring loaded indent which extends from the interior of the smaller diameter tube through an opening near the end of the larger diameter tube when at maximum permitted extension.
The means for capturing and holding the wheel brace on the developed lever will be determined by the specific type of wheel brace to be used. For large vehicles such as trucks and agricultural equipment, a socket extension wheel brace with a sliding T-bar is typically employed. In that case, the capturing and holding means will preferably comprise a first collar adjacent one end of the developed lever and a second collar spaced from the first collar by a distance enabling capture of the sliding T-bar therein. The arrangement is such that force is transmitted to the sliding T-bar at the points of support in the first and second collars and through the housing in which the sliding T-bar connects with the socket extension. This effectively distributes the force applied to the T-bar and mitigates the bending thereof.
The first collar can comprise a ring, square or round tube section which is either welded to the developed lever or, more preferably, fitted to the developed lever by means of a threaded stem which passes through opposing walls of the developed lever and which can be tightened or loosened by means of a wing nut or the like. This arrangement enables the T-bar housing of a socket extension to be accommodated below the developed lever while the T-bar is retained in a substantially parallel relationship with the developed lever.
The second collar can also comprise a ring, square or round tube section but this is preferably welded to the developed lever at a position between one third and one half the length of the non-extended developed lever measured from the first collar. The second collar has internal dimensions which are greater than the cross-sectional dimension of the T-bar and for this reason a spring-clip, or threaded stem can be provided to ensure that the T-bar is firmly held by the developed lever.
In one embodiment, the developed lever for use with a socket extension wheel brace incorporates a metal band on the side opposing the side on which the collars are located. The band is welded near each end of the developed lever and curves outwardly from a mid region of the developed lever. It is supported in a raised elevation by a small plate extending perpendicular to the developed lever which is located directly opposite the second collar. The purpose of this metal band is twofold. Firstly it resists the bending of the developed lever under the application of force applied to the lever during operation. Secondly it dampens the recoil of the developed lever when a nut is suddenly loosened.
As noted previously, the capturing and holding means depends on the type of wheel brace used. For small vehicles such as automobiles, which employ cross-braces or xe2x80x9cL-shapedxe2x80x9d wheel braces, the capturing and holding means will suitably comprise a pair of spaced brace supports extending, respectively, perpendicularly from one end of the developed lever and a shortened distance therefrom, which retain a brace arm in parallel spaced relationship with the developed lever and prevent lateral movement thereof. Suitably, a brace support on the end of the developed lever comprises a recessed plate welded over the end of the developed lever from which it projects. The recessed plate has turned down projecting ends so that the arm of a cross-brace extending at right angles to the developed lever can be retained in situ.
The brace support which is spaced from the end of the developed lever also preferable comprises a recessed plate but which is welded about the body of the developed lever.
In use, the ground engaging wheel brace support is placed in a vertical position parallel to the wheel ensuring that it is on stable level ground and will not slip or sink. The socket of a socket bar (in the case of large vehicles) is placed on a selected wheel nut and the socket bar is located on one of the projections of the wheel brace support so that the socket bar is maintained in a substantially horizontal arrangement. The socket extension is then fitted into the housing of the sliding T-bar and the developed lever is connected to the sliding T-bar through its collars so that the developed lever extends over the sliding T-bar and the housing on the T-bar is adjacent to the first collar. The inner extendable tube of the developed lever is then extended to its required length. The developed lever rests on the T-bar housing and upon the extendable tube being manually depressed at its outer free end, transmits all the energy of rotation to the socket extension, enabling a maximum torque to be applied to the nut with less energy than would normally be required, to thereby loosen the nut. Further, because of the location of the collars on the developed lever, there is no one point of the sliding T-bar which is overly stressed; in effect the energy of rotation is dissipated along the entire length of the T-bar to the housing, thereby avoiding any bending of the T-bar as was previously the case.
Operation of the developed lever adapted for use for smaller vehicles such as automobiles is by an entirely analogous procedure to that defined above.